BR112017009987B1 - REACTOR WITH RADIAL CARGO DRAINAGE AND GRAVITANT CATALYST DRAINAGE AND CATALYTIC REFORM PROCESS OF A GASOLINE TYPE MIXTURE - Google Patents

Abstract

the present invention describes a type of radial bed reactor that allows the use of small amounts of catalyst. application of the reactor to the regenerative reform process.

Description

FIELD OF THE INVENTION

[0001] The invention refers to the radial bed reactor technology with gravitational catalyst circulation and transverse flow of the load. The invention applies more especially to the catalytic reforming of gasolines with continuous catalyst regeneration. The invention makes it possible to use very small amounts of catalyst according to a radial bed technology, a feature that is not possible with current technologies.

[0002] The present reactor allows to reach PPH greater than 50 h-1 (ratio of load flow over the catalyst mass).

EXAMINATION OF THE PRIOR TECHNIQUE

[0003] In the prior art, which refers to radial bed reactors, patent US 6221320 can be cited which makes a summary of conventional technologies (figures 10 to 11). According to the state of the art, the catalytic bed within a Radial bed reactor is bounded by two grids, an inner grid and an outer grid. More precisely, they are generally distinguished: • An internal grid that delimits the central collector of gaseous effluents, • An external grid that delimits the load's supply volume in the gaseous state.

[0004] The process fluid (or charge) arrives by the external volume defined between the outer shell and the outer grid. It then traverses the catalytic bed substantially horizontally and orthogonal to the circulation of the catalyst, which is gravitating, that is to say substantially vertical from top to bottom.

[0005] The process fluid in radial flow and the catalyst in gravitational flow are separated by the outer grid which generally has a cylindrical shape of the same substantially vertical axis as the outer grid.

[0006] The cylinder defined by the inner grid serves as a central collector to evacuate the gaseous effluents from the reaction zone comprised between the outer grid and the inner grid and, therefore, substantially annular in shape.

[0007] The restrictions linked to the technology in radial bed are multiple. In particular, gas velocities across the catalytic bed are limited to:• prevent cavitation at the bed inlet• avoid blocking the catalyst at its exit against the internal grid, also called "pinning" in English• reduce losses load (function of speed and bed thickness).

[0008] For reasons of homogeneous distribution throughout the height of the catalytic bed, a perforated grid designed to create pressure drop can be added over the central collector.

[0009] For construction reasons, it is necessary to leave enough space between the inner grid and the outer grid. When all restrictions are accumulated, the minimum volume of catalyst that can be contained in a ferrule is very restricted. In general, according to the prior art, the maximum PPH is of the order of 20 h-1, while the reactor according to the present invention allows to reach PPH greater than 50 h-1.

[0010] The document US 4,411,870 describes a reactor containing a plurality of reaction chambers, each of these chambers comprising an annular zone for the catalyst and the charge being distributed in the different reaction zones in order to realize a uniform flow of reactants in the different zones. This document does not provide any information about the geometric characteristics of said reaction zones.

BRIEF DESCRIPTION OF THE FIGURES

[0011] Figure 1a represents an exploded view of the ferrule 1 of the reactor according to the invention, but which does not contain the module M, in order to clearly visualize the floor 13 that supports said modules.

[0012] Figure 1b is an exploded view of the reactor according to the invention in which it is possible to see the M modules and their connection with the upper part of the ferrule 1, as well as the catalyst inlet legs 10 and the legs of racking 11.

[0013] Figure 2a represents a section of the reactor in top view that allows to see the modules M, the catalytic zone of each module 4 and the external 2 and internal 3 grids that define said catalytic zone.

[0014] Figure 2b represents a section of the reactor in a side view that allows viewing the input of load 8 and the output of effluents 12 as well as the volume 9 of load distribution in the set of modules M and the entire volume 7 of collection of the effluents from each module M.

[0015] Figure 2c represents a module M in side view and allows a good understanding of the corresponding entity inside the reactor. BRIEF DESCRIPTION OF THE INVENTION

[0016] The present invention describes a type of feeder reactor, designed to use a small amount of catalyst in the order of a ton and which can advantageously constitute the first reactor in the series in a gasoline catalytic reforming unit comprising according to Prior art three to four reactors positioned in series.

[0017] This reactor can be called modular in the sense that it consists of a set of identical modules that work in parallel and are contained within a single shell.

[0018] More precisely, the reactor, according to the present invention, is a reactor with radial flow and with gravitational flow of the catalyst consisting of a set of substantially identical M modules contained within a single ferrule 1, which has means for introducing the catalyst 10 located in the upper part, and means for evacuating said catalyst 11 located in the lower part 7, and a means for introducing the load through an upper central pipe 8 and a means for evacuating effluents through a lower central pipe 12, each module having the form of a cylinder delimited by a substantially vertical outer wall 2 and a substantially vertical inner wall 5, the two walls together defining an annular zone 4 containing the catalyst, and the outer 2 and inner walls 5 of each module being permeable to the gas load and to the gas effluents, and generally consisting of a Johnson grid or equivalent, said modules being positioned vertically. symmetrical globally in relation to the center of the ferrule 1, and the effluent outlets of each module being made by the central collector 3 of each module that communicates with the lower part 7 of the ferrule 1, the internal volume 9 and the lower volume 7 being separated by a floor 13 which seals between the two volumes and also allows to support the modules M, and the radial bed thickness of each module M being comprised between 10 and 400 mm, and preferably comprised between 50 and 250 mm.

[0019] Among the possible arrangements of the modules within the ferrule1, alignments of said modules according to several concentric circles can be cited. In general, whatever the special arrangement of the modules within the ferrule, they are distributed approximately symmetrically with respect to the center of the ferrule 1.

[0020] Preferably, inside the reactor with radial flow according to the present invention, the M modules are evenly distributed in the inner part of the ferrule according to a circle.

[0021] Preferably, the reactor according to the present invention has a number of modules comprised between 3 and 12, and most preferably comprised between 5 and 10.

[0022] Preferably, the reactor according to the present invention has for each module M a height to diameter ratio of between 3 and 30, and most preferably between 7 and 11.

[0023] Advantageously this reactor can be used as the top reactor in a catalytic reforming process of a gasoline-type mixture that uses a series of three or four radial bed reactors. In this case, it is possible to describe the flow of the charge and the catalyst as follows: • the charge enters inside the ferrule 1 through the inlet pipe 8 located at the top of the reactor and then occupies the internal volume 9 from which it it penetrates the internal part of each module M, crossing the external grid of said module 2 for this, • the charge passes through the catalytic bed contained within the annular zone 4 of each module M and the effluents resulting from the catalytic reaction are collected inside the central collector 3 of each module, • the effluents from each module are grouped within the lower volume 7 of the ferrule 1, and are evacuated from the reactor by the outlet piping • the catalyst is admitted into each module by an inlet piping 10 and drains so gravitating in the annular zone 4 of each module, and then evacuated from the module by an outlet pipe 11.

[0024] In a catalytic reforming process of a gasoline mixture using the reactor according to the present invention, the PPG (rate of charge flow rate to catalyst weight) is greater than 50 h-1, preferably greater than 100 h-1.

[0025] In a catalytic reforming process of a gasoline mixture using the reactor according to the present invention, the charge may have a paraffin content that can go up to 70% by weight and even be an entirely paraffinic charge.

DETAILED DESCRIPTION OF THE INVENTION

[0026] The invention consists essentially in realizing a set of radial bed "modules" of small sizes that allows to reach PPPH higher than in traditional reactors, the set of these modules being contained within a single shell.

[0027] The following description is made with the aid of figure 1a which represents the reactor in exploded view and without module, in order to clearly visualize the outer shell 1 and figure 1b which represents the reactor in exploded view that contains the modules .

[0028] Figures 2a and 2b represent a reactor in top view (figure 2a) and side (figure 2b).

[0029] The load enters inside the ferrule 1 through the piping 8 located at the top. The cargo then occupies the internal volume 9 from which it penetrates into the internal part of each module, crossing the external grid of said module 2.

[0030] The charge crosses the catalytic bed contained within the annular zone 4 of each module and the effluents that result from the catalytic reaction are collected within the central collector 3 of each module. The effluents from each module are grouped within the lower volume 7 of the ferrule 1.

[0031] The internal volume 9 and the lower volume 7 are separated by a floor 13 that makes a seal between the two volumes and that also allow supporting the M modules.

[0032] The catalyst is admitted into each module by an inlet pipe 10. It flows gravitationally in the annular zone 4 of each module, and is then evacuated from the module by an outlet pipe 11. There is at least one outlet pipe. inlet 10 and one outlet piping 11 per module.

[0033] The modules are in the form of cylinders delimited by a substantially vertical outer wall 2 and a substantially vertical inner wall 5, the set of two walls defining an annular zone 4 containing the catalyst. The outer 2 and inner 5 walls of each module are permeable to load and gas effluents, and are generally constituted by Johnson grid or other equivalent means. These modules are positioned inside a single shell 1 that serves as a volume for the supply of process gas from the top 6 and the evacuation of effluents.

[0034] The effluents of each catalytic zone are then collected inside a common volume 7 located in the lower part of viola 1. The modules allow to make catalytic beds with very small thicknesses, which considerably reduces pressure drop restrictions.

[0035] The height over diameter ratio of each module is generally comprised between 3 and 30, preferably comprised between 7 and 11.

[0036] The radial bed thickness of each module is between 10 and 300 mm, generally less than 100 mm (a mm = 10-3 m).

[0037] The PPH (ratio of charge flow to catalyst weight) is generally greater than 50 h-1 preferably than 100 h-1.

[0038] The centers of each module are advantageously positioned along a circle, as shown by way of example in figure 2a for a reactor that contains 6 identical modules.

[0039] The number of modules is generally comprised between 3 and 12, preferably comprised between 5 and 10.

[0040] The central collectors 3 of each module communicate with the same volume 7 located at the bottom of the ferrule 1 that allows the evacuation of the effluent through the outlet pipe 12.

[0041] On the upper part of the ferrule 1 there are tie-rods 6 that allow to keep the modules M resting on the plate 13. This plate 13 is watertight to avoid any mixing of the load contained within the upper volume 9 with the effluents gathered within the lower volume 7 .

[0042] Said plate 13 is supported by columns and reinforcement beams to support the weight of the modules (filled with catalyst).

[0043] Each M module has a fixing plate to plate 13, this fixation can be performed by any means known by the professional.

[0044] The reactor also allows visual inspection through an opening, the reactor once assembled, notably for the external grids, and internal grids, at least in part. The placing in parallel of several modules also makes it possible to consider condemning one of them in case of failure, while continuing to make the system work on the remaining modules.

[0045] The proposed system allows, therefore, the achievement of high PPH objectives to optimize the reaction performances of the process, while proposing a realistic mechanical concept, scalable, flexible and easy to maintain.

EXAMPLES

[0046] The following examples allow to illustrate the dimensioning of a reactor, according to the invention, intended to be positioned on top of a regenerative reforming unit that handles a load whose naphtha flow is 150 t/h of load: • Example 1 represents the reference case not according to the invention, • Example 2 represents the performances of a unit according to the invention equipped with a top reactor with the same operating conditions and the same total quantity of catalyst than in example 1.• Example 3 illustrates the performances of a unit that has the same characteristics as that of example 2, but that handles a more severe load.

[0047] In example 1, a hydrocarbon charge is treated in four reaction zones arranged in series within four reactors. The distribution of the catalyst within the reactors is as follows: 10%/20%/30%/40% by weight relative to the total weight of catalyst.

[0048] The total amount of catalyst is 75 tons.

[0049] Table 1 gives the composition of the hydrocarbon charge: • initial boiling point 100°C, final boiling point 170°C:

[0050] The catalyst used in the reactors comprises a chlorinated alumina type support, platinum and is promoted with tin.

[0051] The charge heated to 514°C is thus successively treated within the four reactors with an intermediate heating of the effluent to 514°C before its introduction into the next reaction zone.

[0052] The operating conditions in the four reaction zones are given in table 2. These conditions were chosen to produce a recovered reformate at the output of the fourth reactor of which the index RON (Research Octane Number according to Anglo-Saxon terminology) is equal to 102.

[0053] Example 2 corresponds to example 1, except that the hydrocarbon charge is treated in five reactors arranged in series with a distribution of the following catalyst: 2%/10%/ 20%/30%/38% by weight in relation to the total weight of catalyst. The small reactor according to the present invention is positioned on top. He is reactor 1.

[0054] The total amount of catalyst is 75 tons to treat a hydrocarbon charge flow of 150 t/h.

[0055] As in example 1, the charge and effluent of one reaction zone are heated to 514°C before entering the next reaction zone.

[0056] The operating conditions in the reaction zones of the reactors are grouped in the following table 3:

[0057] The dimensioning of the first reactor is performed according to figures 1 and 2 with the geometric characteristics described in table 4.

[0058] Using the small top reactor according to the invention, the temperature drop in this first reaction zone is limited, but also in the other zones 2, 3, 4 and 5.

[0059] Since the catalyst activity is a function of the average temperature in the catalytic bed, limiting the temperature drop, consequently improving the yield of aromatic compounds, as indicated in table 5.

[0060] This temperature increase within the catalytic beds greatly impacts the activity of the catalyst. For the same amount of catalyst as illustrated below, the gain in aromatic production allows for an improvement in RON of 1.6 points.

[0061] Example 3 allows to illustrate the contribution of the invention from the point of view of load severity. A load is even more severe the higher its paraffin content. With an approach identical to the previous state, it is necessary to increase the amount of catalyst or the temperature at the inlet of the reactor to maintain the RON of the reformate. Example 3 is intended to handle a load, such as that described in table 6, much more severe load than that of example 1.

[0062] With the same operating conditions as those described in tables 3 and 4, the RON of the reformate is maintained at 102 despite a 15% increase in weight of the amount of paraffins within the load.

Claims (5)

1. Reactor with radial load flow and catalyst gravitational flow, characterized by the fact that it consists of a set of substantially identical modules (M) contained within a single shell (1), and regularly distributed in the internal part of the said ferrule according to a circle, each module (M) having a height to diameter ratio of between 7 and 11, and each module (M) having catalyst introduction means (10) situated on top, and means for evacuating the said catalyst (11) located in the lower part (7) of the ferrule (1), and a means of introducing the load through an upper central piping (8) and a means of evacuating the effluents through a lower central piping (12), each module having the form of a cylinder delimited by an outer wall (2) substantially vertical and an inner wall (5) substantially vertical, the set of two walls (2) and (5) defining an annular zone (4) containing the catalyst , and stop them external (2) and internal (5) des of each module being permeable to gas load and gas effluents, and consisting of Johnson grid or equivalent, said modules being positioned vertically in a globally symmetrical manner in relation to the center of the ferrule (1 ), and the effluent outlets of each module being made by the central collector (3) of each module that communicates with the lower part (7) of the ferrule (1), the internal volume (9) of the ferrule (1) and the lower volume (7) of the ferrule (1) being separated by a floor (13) which seals between the two volumes and also allows to support the modules (M), and the radial bed thickness of each module (M) being comprised between 10 and 400 mm, and preferably comprised between 50 and 250 mm, and the number of modules being comprised between 5 and 10. 2. Catalytic reform process of a gasoline-type mixture using the reactor as defined in claim 1, positioned at the top of the series of reactors that constitute the reform unit, characterized by the fact that: • the charge enters inside the ferrule ( 1) through the inlet piping (8) located at the top of the reactor and then occupying the internal volume (9) from which it penetrates into the internal part of each module (M) for this, crossing the external grid of said module (2),• the charge passes through the catalytic bed contained within the annular zone (4) of each module (M) and the effluents resulting from the catalytic reaction are collected within the central collector (3) of each module, and then• the effluents from each module are grouped within the lower volume (7) of the ferrule (1), and are evacuated from the reactor through the outlet pipe (12), • the catalyst is admitted into each module by an inlet pipe (10) and flows gravitationally in the annular zone (4) of each module, and d then it is evacuated from the module by an outlet pipe (11). 3. Catalytic reforming process of a gasoline-type mixture, according to claim 2, characterized in that the PPG (rate of charge flow over catalyst weight) is greater than 50 h-1, preferably greater than 100 h-1. 4. Catalytic reforming process of a gasoline-type mixture, according to claim 2, characterized in that the charge has a paraffin content that can go up to 70% by weight. 5. Catalytic reforming process of a gasoline-type mixture, according to claim 2, characterized by the fact that the charge is entirely paraffinic.

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